435P - Use of Bevacizumab in Anticoagulated Recurrent Glioblastoma Multiforme Patients: an Australian Experience

Abstract

ABSTRACT Aim: The prognosis for relapsed glioblastoma multiforme (GBM) remains poor despite advances in combined modality treatment plans in recent years. Bevacizumab, a monoclonal antibody against vascular endothelial growth factor (VEGF) has been shown to improve progression free survival (PFS) in first line setting with no impact on overall survival and mixed results in relation to quality of life and cognition. As there is no standardized protocol in recurrent GBM setting, many clinicians have tried Bevacizumab in the recurrent setting with some hopeful results based on the principle that GBMs are highly vascularized tumors. Use of bevacizumab in this setting is often pursued with caution because of concerns in safety for both thrombosis and bleeding events, especially in a patient population that already has a high incidence of venous thromboembolism (VTE) and are often in full anticoagulation with low molecular weight heparin (LMWH). We aim to investigate the effectiveness and safety in using bevacizumab in anticoagulated recurrent GBM patients. Methods: In this retrospective analyasis, we searched through our own database from 1998-2014 and identfied all patients who has received bevacizumab in the recurrent setting (outside clinical trials). We then looked through medical records and databases in search of survival data, toxicity effects, dexamethasone doses. Results: There were 36 patients (often heavily pretreated) on anticoagulation prior to bevacizumab commencement (including 35 for VTE and 1 for atrial fibrillation). Out of these 36 patients, we identified 2 cases with further VTE events and 2 cases with epistaxis and 1 patient was recorded to have bowel perforation. We also recorded a median survival time on Bevacizumab of 5.37 months and a median overall survival time of 16.7 months with a significant reduction in steroid burden. Conclusions: In summary, Bevacizumab can be safely added to recurrent GBM patients that are already anticoagulated for venous thromboembolism with tolerable toxicity profiles and reasonable survival outcomes. Disclosure: All authors have declared no conflicts of interest.